Stamp-mill.



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II. L. DOHERTE.

l STAMP MILL. APPLICATION FILED JAN. I7. 19H,

Patented Aug. 1, 1916.

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. HENRY L. DQHERTY, or NEW YORK, N. Y.

STAMP-MILL.

Specification of Letters Patent. v

' ratenteanug. 1,1916.

Application filed January 17, 1911. Serial No. 603,084.

To all (whom it may concern:

Be it known that I, HENRY L. DoHnR'rY, a citizen of the United States, and a resident of New York city, inv York and State of New York, have invented certain new and useful- Improvements in Stamp-Mills, of which the following is a specification.

This vinvention relates to a stamp mill and, in particular, to a variety of such apparatus in which the stamp and stem are made hollow and the material to be crushed is fed down through the hollow stem onto the die.v

The object of myv invention is to provide a machine that will finely vcrush such materials as coal, coke, lime, etc., 'which are very difficult to reduce 1 a part side elevation and lpart vertical section through one of the stamps on the line A B of Fig. 1. Fig. 3 is a part end elevation of the mill showing the gearln'g connecting the two coperating cam head of one of the stamps on of Fig. 5. Fig. through the same on stamps; 1, 2 and 3 respective stam-ps, Y

4, 5 and 6, designate the tappets on stamps 1', 2 and 3, respectively.v I 7, S and9 lare the dies of'the respective stamps which are supported the anvil block 10. y 11 and 12 are the end walls of the mortar, while 13 and 14 are the side walls.

15 isV a concretev foundation'or mortar block onwhich the anvil block 1() is supported. A suitable heavy frame, composed of the two uprights 17 and 17', braces 18 and guides 19 and 19', affords supportsfor the bearings 20 and 20 and 21 and 21 of the cam shafts 22 and 23, respectively, and guides for the stamp stems. Cams, 24, 24 and 24 and 25, 25 and 25 mounted on shafts 22 and 23, respectively, engage the tappets of the stamps and lift the stems, on the revolution of the shafts 22 and 23. Keys the county of Newn grinding apparatus of the ordinary kind, with the minimum eX-f f shafts ofthe mill.v Fig. 4 is a horizontal section through'the' the line E F 5 is a' vertical section` the line G H of Fig. 4. 1, 2, 3, designate the stems of the several are the shoes of the'.

engages the tappet, at

26,'serve to fasten the cams on their shaft. A pulley, 27, mounted upon either of the shafts 22 or 23, imparts motion to both shafts through the connecting gear 28-28- By means of the gear wheels 28-28 it is seen that the two cam shafts are compelled to rotate in absolute unison, but in opposite directions. The cams on the respective shafts are arranged in coperating couples, the cams 24 and 25, for instance, being so set on their respective shafts vthat they engage and clear the bottom of the tappet 4 at exactly the same instant but on opposite sides of the stem 1. Cams 24 and 25, and 24" vand 25, cooperate' with 'respectA to the tappets 5 and 6, respectively, in the same manner as cams 2 4 and 25. By this device, which constitutes an important novelty of this invention, I am enabled to transmit Athe lifting stress to the ta pet ofthe stamp in an absolutely vertical direction without any unbalanced horizontal component (except the turning movement of the cams on the tappet) such as exists when the tappets are lifted by a single cam acting on one side of the tappet and at the Sametime impart a motion of rotation to the stamp. There is thus very little friction of the stems in the guides and the loss of power in overcoming the friction is thus very muchreduced. The coperating cams on thetwo shafts, as already pointed out, exert balanced stresses upon the tappet both in reference to lift and rotation, with the result that friction in 4the guides is reduced 'to a practically negligible quantity. When only a single ycam I a given time, there is a frictional resistance of 4serious magnitude, by they stamp, both as respects lifting and rotation. This is due tothe heavy pressure by the stem upon the guides, due to the tilting'stressexerted by the' single cam acting on a lever arm equal to the distance lof the circle of the contact ring on the tappet from the aXisy of thev stamp stem.v With two cams, as in my invention, engaging the tappet at the same timeV and exerting a turning stress and a lifting stress in the same, respective, directions* the tilting stress that forces the stemagains't'the guides, in the case of a single cam, is practically eliminated. The initial resistance of the stamp to rotating is therefore much lessened. Therefore the slip between the cams and tappet will be much less than where a single pain is used, and a much higher speed Q15' rotation will be communicated to the stamp. This improved method of operation of my invention, as compared with that of similar apparatus known to the art, enables me to secure a very important advantageous and improved result. This is a marked increase in the positive grinding action eX- erted upon the material between the shoe and die, which results in a very marked increase both in the output and in the fineness of the same. In the stamp mills at present in use the friction in the guides absorbs from 15 to 20 per cent. of the total power required for the opera-tion of the battery.

' This power loss I, to a large extent, eliminate by my invention, as well as increase the e'liciency of the working.

The shoes, 1, 2 and 3, are attached to their respective stems, 1, 2 and 3, in the manner shown in detail in Figs. 4 and 5. The face of the annular wall of the stem contains recesses 29, 29 which receive the projecting tongues 30, 30 on the upper face of the shoe. Key-ways, 31, 31, in the annular wall of the stems and corresponding` key-ways, 32, 32, in the tongues carried by the upper faces of the shoes permit of the insertion of the keys 33, 33, which hold the shoes rigidly attached to their respective stems. The shoes in the construction shown are made of the same internal and external diameter as the stamps themselves. It is obvious that, if for any reason preferred, the external diameter of the shoes may be made either greater or less than that of the stamp itself.

The dies 7, 8 and 9 are set into the face of the anvil block 10 and are thus held in place, but may be easily removed for the insertion of new dies. The dies should exactly correspond in crosssection with the shoes and have therefore a hollow core the same as the shoes. This is kept filled with -the material to be crushed when the mill is working. It is of course possible to make either the shoes or dies of a greater diameter, but such a construction invariably results in the channeling of the piece having the greater diameter, which seriously interferes with the smooth working of the stamps.

35 and 35 are small screw-conveyers which take up the crushed material discharged from the stamps and move it longitudinally of the mortar to the discharge chutes 36 and 36, respectively. These deliver the crushed material into the conveyers 37 and 37 respectively, which run along the whole row of batteries when a plurality of batteries are used in the one plant. Any preferred method, other than the one illustrated and described, may be used to eject the crushed material from the mortar. For instance, the small conveyers 35, 35 may be omitted altogether, and longitudinal slots left in the bottom of the mortar through which the crushed material may be discharged directly, over inclined chutes, into the conveyers 37 and 37. Both of the conveyers 37 and 37 are driven from a suitable jack shaft (not shown), the belt for one of the conveyers being, of course, crossed. The pulleys 38 and 38 are set on opposite ends of the respective shafts 34 and 34 of the conveyers 35-35- Suitable bearings, 39 and 39, respectively, support the shafts of the respective screws 35 35. The top 40 of the mortar 16 has large openings 41, 42 and 43. Corrugated disks, 44, 45 and 46, of rubber, leather, canvas or some equivalent material, are fastened, respectively, over the openings 41, 42 and 43. These disks areperforated centrally so as to permit of the passage of the stamp stems through them. Suitable collars, 47, attach the disks to the respective stamp stems, while collars 48 hold the outer edge of each disk tightly in contact with the top plate 40. The interior of the mortar is thus tightly inclosed and rendered practically dustless. Since I prefer to operate the stamps at a high speed on a low drop, the depth of the corrugations of the disks need not be very great to permit of the movement of the stamps.

Another novel and important feature of my invention is the method of feeding the raw material to be crushed to the stamps. A feed bin, 49, is supported in an elevated position directly over the battery on the beams shown. Discharge hoppers, 50, 51 and 52, are located directly over the respective stamps, 1, 2, 3. Short feed chutes, 53, 54 and 55, project from the discharge openings of the respective hoppers into the hol low core of the stems. Suitable slides or gates, 56, 57 and 58, respectively, serve tocontrol the flow of material from the hoppers to the stamps.

The material to be ground should be first run through an ordinary rock breaker and then over a screen or grizzly so that nothing over two inches in size (for the stamp mill shown) shall be fed to the stamps. The drop with the stamp mill shown in the drawings is very low-only about two inches. This fact, of course, limits the size of the fragments of coke or other material which may be fed to the stamps. With a higher drop the size of the material which may be used is, of course, increased. The properly sized material is charged into the bin 49. The driving shaft (not shown) which operates the cam shafts of the batteries is now thrown in gear and the battery put in operation. The slides or gates 56, 57 and 58 are now partly opened so as to permit of the proper amount of material passing through the respective chutes to the interior passage ofthe stamp stems. The material falls onto lthe dies and on the lift of the stamps works out onto the annular crushing face of the dies. These latter, as shown, are simply rings of a thickness corresponding to that of the stamp shoes. The hollow core of the ring is, of course, kept iilled with the material fed to the stamps. As the dies Wear away the filling of the core, of course, wears away correspondingly. There is thus no obstruction to the feed upon the wearing away of the dies such as would take place were the die made solid. As the dies wear, the wear is compensated for by inserting special chuck blocks, 59, beneath the dies. Owing to the low drop which I prefer, I makelthe stamps very heavy. I thus lose nothing in crushing power through the reduction in the drop. It is to be understood that I do not limit myself to a low drop for the stamps since my invention can just as well be built with a drop of 8 to 10 inches as with a two inch drop.

I prefer to operate my stamps at a Very high speed-250-300 drops per minute. This also, however, is a matter to be regulated according to the personal preference of the operator.

Having described my invention, what I claim is:

l. A stamp mill comprising in combination, a plurality of stamps, a tappet on each of said stamps, means for simultaneously applying balanced, substantially vertical lifting stresses and balanced turning stresses at diametrically opposite points of said tappets to lift and impart a comparatively high speed of rotation to said stamps, said lifting and turning means comprising in combination two directly geared cooperating cam shafts, a plurality of cams mounted on each of said cam shafts, and staggered relative to each other, a pair of said cams, one

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cam on each of said shafts, being adapted upon rotation of said shafts to simultaneously engage and disengage the tappet of the stamp with which it is cooperating on opposite sides longitudinally of the shafts.

2. A stamp mill including in combination a plurality of stamps, atappet on each of said stamps, means for applying balanced lifting stress and balanced turning stress at opposite points to said tappets to lift and impart a comparatively high speed of rotation to said stamps, saidlifting and turning means including cooperating cam shafts, on opposite sides of said stamps, a plurality of cams mounted on each of said shafts and staggered relatively on said shafts7 one of said cams on each of said shafts being adapted upon rotation of said shafts to simultaneously engage and disengage the tappet of the stamp with which it is cooperating on opposite sides longitudinally of the shafts.

3. A stamp mill comprising a plurality of stamps, balanced lifting and turning means comprising in combination a tappet on each of said stamps, and a set of cams arranged to engage each of said tappets, two longitudinal shafts, each located on opposite sides of said stamps and each carrying a cam of each set for each tappet, whereby the cams of each set will simultaneously strike the tappet at points outside the longitudinal center thereof, and means for simultaneously revolving the shafts.

Signed at New York city in the county of New York and State of New York this 16th day of Jan. A. D. 1911.

HENRY L. DOHERTY.

Witnesses:

J. M. MCMILLIN, F. L. BLACKBURN.

Washington, D. C. 

